I came across the free, open source Hesk Helpdesk (http://www.hesk.com) while I was looking for a light weight help system for a project that was starting up. The project has since been put on hold, but Hesk is still a great application for a helpdesk/knowledge base. Hesk is offered as a free downloadable PHP script, as well as a Hosted Version if you do not have a server. The hosted version will cost you $20 US a month. You can also by a license for the downloadable version for $39.95 US to remove the Hesk branding.

While this application is great…

Allows unlimited staff

Granular permissions to the system and help desk categories

Excellent knowledge base built in

Innovative system that doesn’t require user accounts for clients

It is lacking a few features. I plan to use this application to respond to clients from a number of different projects. As such, it would be nice if they didn’t see ALL of the problem types when submitting tickets. Because Hesk is open source, we can make a few tweaks to get directly to a specific problem type.

Hesk also allows custom fields for your tickets, but it shows all custom fields on all problem types. This can get confusing for users in a multi-project environment. I’m developing a little hack to get around this limitation.

I’ve outlined both of these changes required on my wiki, you can take a look here.